yellow brake light, triangle, hybrid sys, no codes

my apologies if redundant but my searches have not come up with a solution. I changed the HV battery and drove a thousand miles up and back from the mountains. Changed oil and air filter and washed car, turned car back to daughter. Wouldn't shift into drive, yellow brake(exclamaiton), triangle and red car with exclamation. OBD codes on my cheap reader do not come up,thought the first time we thought we got an PAO80? but not certain and has never showed up again. When you clear codes and shut off and restart the car will function fine. It seems....that if i hold the brakes down for a long time the codes will reappear but this is not reliably repeatable. I bought Torque and a blue tooth sender which will turn the lights out but the car needs to be reset by my cheapy obd meter to work. I bought a TIS cable and software which i installed on an spare laptop, my install was not wholly successful though it could see the car and pick up the VIN and i thought....that it actually turned on the HV fan which has not been successful since. The sellers tech then did a remote install which seems about as successful as mine. I can see the systems in the "grid" and query them but then tests are seemingly unsusessful and then windows dies on me. i HAVE NOT tried the cable test since the tech install but the middle portion seemed bad when i ran the test after my install.The OBD does not seem to communicate either. I have checked the air filter box, the brake fluid , changed the brake switch. Torque doesnt show any thing outwardly odd but not sure exactly where to look on the 40 sensors. HV cells seem pretty close in voltage and Temp.
I will take to Lucious to make sure daughter is safe but driving me nutty. Any suggestions?? Thaks

 

will get Dr Prius, thanks. 143K, new battery(did not check build date) I did install. Toyota of Oakland is 2 blocks away and heavy spousal pressure to go there but i am holding out for awhile for an internal fix. I did leave a light on an had run down the little Toyta battery after the problem had started. It is less than 2 years old. I did an out of car recharge and seems to be holding above 12 v but will check this am. Arts has a good vibe. The damn car was only about a mile from Luscious before i took it back! Had i known about them would have gladly taken there at the time.

 

ok got some codes finally with the TIS.Not good ones i think
1 Hybrid Control P0AA6 Detail Code 2 - 526
2 ABS- C1241 - Low or High Battery
3 ABS 1310 Detailed freeze 156 HV Malfunction, Capacitor Mode -OFF
4 ABS 1378 Capacitor

HV -OK, also by dr prius and torque cells look good , impedence? was 19 across all 14
Gateway showed a B1271 which i took was from when i replaced the meter screen, "not active"

Any good places to look other than the tranny issue. Seems worse now as i have to clear codes almost every stop

thaks

 

oh and the 12v battery was a good 12.37 this am

 

well, made an appointment w \lucious on friday, but decided to take it to Toyota 2 blocks away. I gave them the Toyota notice outlining the codes and described transaxle problem. Pretty sure it will be a waste of $220 as only the 526 code shows(hopefully my ineptness just didnt find) and i have heard that Toyota won't step up without both codes. Maybe they will find the currant leak somewhere due to my HV battery swap. Cheers

 

sorry for the the delay and a huge thank you to you all especially rjparker and then Luscious for the technical bulletin which i took to Broadway toyota here in Oakland.They fixed it under the warrantee at 140000 miles!! Runs great, hoping for another 140000. Cheers, mike